About Lymphangioleiomyomatosis
Lymphangioleiomyomatosis results from uncontrolled proliferation of LAM cells, which are smooth muscle-like cells of unknown origin (possibly derived from perivascular epithelioid cells, PEComas). TSC-associated LAM results from somatic TSC1 or TSC2 mutations in LAM cells leading to constitutive mTOR activation. Sporadic LAM has somatic TSC2 mutations in LAM cells without germline TSC mutations. The TSC complex normally acts as a negative regulator of mTOR signaling; loss of TSC function leads to unchecked mTOR activity driving LAM cell proliferation. LAM cells produce multiple cytokines and growth factors including VEGF, FGF, and HGF that promote angiogenesis, lymphangiogenesis, and further cell proliferation.
LAM is characterized by progressive cystic lung destruction with characteristic features on HRCT of thin-walled cysts of varying sizes distributed throughout both lungs. Progressive air trapping and cyst formation lead to loss of functional lung parenchyma and progressive airflow obstruction. Spontaneous pneumothorax occurs in 40% of LAM patients due to cyst rupture. Lymphatic obstruction by LAM cell infiltration leads to chylous effusions, chylothorax, and ascites. Renal involvement (angiomyolipomas) occurs in up to 80% of LAM patients and can lead to life-threatening hemorrhage. Disease progression varies widely, from slow progression with minimal symptoms to rapidly progressive respiratory failure requiring transplantation. Estrogen dependency is suggested by disease exacerbation during pregnancy and with hormone replacement therapy.
Common Symptoms of Lymphangioleiomyomatosis
Recognizing the signs of Lymphangioleiomyomatosis early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- Progressive dyspnea on exertion
- Chronic cough, usually nonproductive
- Chest pain or discomfort
- Hemoptysis from cyst rupture
- Spontaneous pneumothorax
- Chylous effusions causing fluid accumulation
Who Lymphangioleiomyomatosis Affects
Primarily affects women, with 90% of LAM cases occurring in females of reproductive age (typically 20s-40s). About 30-40% of women with TSC develop LAM; 10% of LAM cases are TSC-associated. Sporadic LAM (80-90% of cases) occurs without TSC in women only. Rare in men, almost exclusively in TSC-associated LAM. Occurs in all populations.
Find Your Next Step
Answer a few questions and we'll point you to the right tools and information for where you are right now.
Side Effect Explorer
Real-world side effect reports from the FDA Adverse Event Reporting System (FAERS). Includes both FDA-approved drugs and investigational therapies from active clinical trials. Click any drug to see what patients reported.
Loading side effect data...
Genetic Testing
Genetic testing can confirm a diagnosis, guide treatment decisions, and identify family members who may be at risk.
Finding labs...
Trusted Lymphangioleiomyomatosis Resources
Reputable organizations and medical references for learning more about Lymphangioleiomyomatosis, including disease registries, foundation resources, and clinical guidelines.